Power-press for bending plates or metal sheets.



J. DREWES. POWER PRESS FOR BENDING PLATES ORMETAL SHEETS.

APPLICATION FILED AFR. I4. I917- Patented Apr. 15,1919.

film IIv/AZ. 7/ 2 J'oh cranes Drewes Hbborney J OI-IANN ES DREWES, 0F GIDEON, NEAR GRONINGEN, NETHERLANDS rownn-rnnss For; zsnnmne PLATES on METAL SHEETS.

Specification of Letters Patent.

Patented Apr. 15,1919.

Application filed. April 14, 1917. Serial No. 162,140.

To all whom it may concern:

Be it known that I, J OHANNES DREWES,

residing at Gideon, near Groningen, Netherlands, have invented certain new and useful Improvements in Power-Presses for Bending Plates or Metal Sheets, of which the fol lowing is a specification.

Keel plates as used in the construction of steel ships are amidship bent to a substantially cylindrical shape, but near the stem and the stern frame such plates have a more or less complicated form as they are here curved in two different directions.

The manufacture of such plates alway causes serious difliculties owing to the fact that it has hitherto been practically impossible to mechanically bend them into the required shape. Under these circumstances it has been common practice to hammer the flat plates, either hot or cold, until they have assumed the desired forms This method, however, as will bereadily understood, takes up very much time, besides laying considerable strain on the workmen. i

Pressing the plates into the desired form, as is for instance done with boiler front plates or fire box plates, is not economical; indeed, even for a small ship quite a number of difierently shaped keel plates are re-- quired, and if for each oflthese distinct forms a special. steel die had to be made, the cost would almost become prohibitive.

Now, it is the object of the present invention to provide simple and efficient means for mechanically pressing plates or metal sheets into the desired form, this object being carried into effect by subjecting the plates to a pressure between a concave die a and a convex matrix (or vice versa), one of said members being stationary while the other reciprocally moves with an invariable stroke. The location of the movable die with respect to the stationary matrixat the end of the stroke may be changed without affecting the extent of the stroke. In this way, the cotiperating die and matrix are adapted to effect the bending of plates to different degrees of curvature.

The annexed drawing shows a machine constructed in accordance with the prin ciples of this invention, Figure 1 being a side elevation, partly a cross section on line B-B in 'Fig. 2, and Fig. 2 being a cross section on line A-A in Fig. 1.

Referring to the drawing, 1 is a heavy frame with a bed or block 2 for supporting the matrix 3. In the overhanging arm 4: of

the frame 1- a shaft 5 is rotatably mounted,

a suitable device (not shown) being provided for imparting a rotary movement to said shaft 5, which by a clutch coupling or the like (not shown) may be thrown into or out of gear.

Near its end the overhanging arm 4 has a recess, and slidably mounted within this recess is a die-carrier6, with a die 15 fastened to it. The diecarrier may be reciprocated in the usual manner through an eccentric portion 7 of the shaft 5, the latter being guided by a journal 8 concentric therewith and located within a suitable bearing of the overhanging arm 4.

The machine described so far has no distinctive features over known powerpress constructions. According to the invention however the eccentric portion 7 is not directly connected with the die-carrier 6, but through the medium of a second eccentric in the form of a cylindrical bush 9 having an eccentric bore for receiving the eccentric portion 7 of the main shaft 5. The bush 9 rotatably fits within a cylindrical bore of a block 10, which in turn may reciprocate in a recess 11 of the die-carrier 6 in a plane at right angles to the axis of the shaft 5.

The bush 9 is provided with a worm wheel rim 12 meshing with a worm on a spindle 13, which extends outside the die-carrier 6 and at the end of which is provided a handwheel (not shown), collars 14 holding the said spindle 13 against endwise movement in the block 10.

Provided the main shaft 5 is stationary, and rotary movement is imparted to the spindle 13, then, when the bush 9 is turned in the one or the other direction around the eccentric portion 7 of the shaft 5, the block 10 with the die-carrier 6 and the die 15 will move up or down, during which movement the block 10 will also move laterally in the recess 11. It is therefore clear that by turning the spindle 13 the operator may adjust the position of the die at the end of the diestroke without disturbing the length of the stroke which is invariable.

If a plate or metal sheet is to be bent to a substantially cylindrical form, a concave matrix having a cylindrically hollowed surface, and a convex die with a correspondingly curved face are used. The plate is placed in the required position on the matrix and the shaft 5 thrown into gear. By

successive pressing operations or strokes of the die 15 the plate is now forced into the desired shape, the die at each stroke being allowed to move toward the matrix over the distance necessary for obtaining the required curvature in each distinct point; this is sim ply done by turning the screw spindle 13 the required angular distance in the one or the other direction during the time the die is not in engagement with the plate to be bent.

It will be understood that the plate is not exactly bent to fit the face of the matrix or of the die; if this were the case, a special die with corresponding matrix would be necessary for each distinctly formed plate. With the new method one die with its cor responding matrix will do for bending plates of any desired curvature lying be: tween rather widelimits, so that in practice it is only necessary to have say four or five differently curved dies each with its corresponding matrix.

For bending plates which have to be curved in two different directions I may use a die with a substantially spherical or otherwise curved face, and a correspondingly hollowed or concave matrix. The plate is then to be passed in different directions through the press and at every die stroke to be subjected to the required amount of pressure until the radius of curvature in every point has the desired value.

There are many changes and alterations that can be made within my invention, and I would therefore have it understood that I do not limit myself to the exact construction herein shown and described but claim all that falls fairly within the spirit and scope of my invention.

What I claim as new and, desire to secure by Letters Patent, is:

1. The method of bending metal plates or sheets into curvilinear formation suitable for the construction of steel ships, consisting in passing the plate in different directions between a concave die and a convex die, and pressing the plate at each working stroke of one of the dies through a varying distance into the other die without bending said plate exactly to the shape of the dies.

2. n a machine for bending" metal plates or sheets, the combination of a concave stationary matrix, a die-carrier reciprocating with respect to said stationary matrix, a convex die secured to said die-carrier, an eccentric for imparting reciprocating move ment to said die-carrier, a block mounted between raceways in a recess of the die-carrier and adapted to reciprocate therein in a plane at right angles to the axis of said eccentric and in a direction substantially at right angles to the direction of motion of the diecarrier, a second eccentric rotatably mounted in said block and embracing the first named eccentric, and means for imparting a rotary movement to the second eccentric to adjust the terminal points of the stroke of the movable die.

3. In a machine for bending metal plates or sheets, the combination of a concave sta-V tionary matrix, a die-carrier reciprocating with respect to said stationary matrix, a

convex die on said diecarrier, an eccentric for imparting reciprocating movement to said die-carrier, an elongated recess in said die-carrier, a block located 1n said recess and displaceable therein, a second eccentric ro- V tatably mounted in said block and embracing the first named eccentric, worm wheel teeth on the periphery of the second eccentric, and a Worm spindle rotatably mounted in the block and meshing with the teeth of the second eccentric.

In testimony whereof I have affixed my signature in presence of two witnesses.

JOHANNES DREWES.

Witnesses: v I

D. KLEIJN, M. ALvAnnz.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents.

Washington, D. 0." 

